[Tagging] start_date variants

[Tobias Knerr]

On 15.02.19 11:03, Stephan Bösch-Plepelits wrote:
> Example: There is this museum, which openened in 2011, but the building is
> much older, it was built in 1725: https://www.openstreetmap.org/relation/1937535

The root of the issue is that two different features (a building, and a
museum inside that building) are mapped as a single OSM element. That's
ok as a shortcut in simple cases, but when the two features have
different names, different Wikipedia links, and different start dates,
they should really be split into two elements: One for the building, one
for the museum.

Generally, I believe that following a "One feature <=> one OSM element"
principle will lead to cleaner data.

Tobias